Reference to XML file in another XML file

Here is a simplified example of my XML file:

<config>
    <app name="a/b/c">
    <app name="x/y/z">
</config>

I've already created subtypes of `DomElement` for my config file, and registered my `ConfigDomFileDescription` in `plugin.xml`.

By convention, `app[name]` corresponds to a relative path of the file minus `.xml` extension: `a/b/c.xml`, `x/y/z.xml`, etc.

For now, all I want is to be able to simply open a file corresponding to the `name` attribute.

Thanks.